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排序方式: 共有220条查询结果,搜索用时 31 毫秒
61.
Sumaiyah Mat Pey June Tan Chin Teck Ng Farhana Fadzli Faizatul I. Rozalli Ee Ming Khoo Keith D. Hill Maw Pin Tan 《PloS one》2015,10(10)
Osteoarthritis (OA) exacerbates skeletal muscle functioning, leading to postural instability and increased falls risk. However, the link between impaired physical function, OA and falls have not been elucidated. We investigated the role of impaired physical function as a potential mediator in the association between OA and falls. This study included 389 participants [229 fallers (≥2 falls or one injurious fall in the past 12 months), 160 non-fallers (no history of falls)], age (≥65 years) from a randomized controlled trial, the Malaysian Falls Assessment and Intervention Trial (MyFAIT). Physical function was assessed using Timed Up and Go (TUG) and Functional Reach (FR) tests. Knee and hip OA were diagnosed using three methods: Clinical, Radiological and Self-report. OA symptom severity was assessed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC). The total WOMAC score was categorized to asymptomatic, mild, moderate and severe symptoms. Individuals with radiological OA and ‘mild’ overall symptoms on the WOMAC score had reduced risk of falls compared to asymptomatic OA [OR: 0.402(0.172–0.940), p = 0.042]. Individuals with clinical OA and ‘severe’ overall symptoms had increased risk of falls compared to those with ‘mild’ OA [OR: 4.487(1.883–10.693), p = 0.005]. In individuals with radiological OA, mild symptoms appear protective of falls while those with clinical OA and severe symptoms have increased falls risk compared to those with mild symptoms. Both relationships between OA and falls were not mediated by physical limitations. Larger prospective studies are needed for further evaluation. 相似文献
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63.
Triantaphyllopoulos K Hussain F Pinart M Zhang M Li F Adcock I Kirkham P Zhu J Chung KF 《American journal of physiology. Lung cellular and molecular physiology》2011,300(5):L691-L700
Oxidative stress plays a role in the pathophysiology of emphysema through the activation of tissue proteases and apoptosis. We examined the effects of ozone exposure by exposing BALB/c mice to either a single 3-h exposure or multiple exposures over 3 or 6 wk, with two 3-h exposures per week. Compared with air-exposed mice, the increase in neutrophils in bronchoalveolar lavage fluid and lung inflammation index was greatest in mice exposed for 3 and 6 wk. Lung volumes were increased in 3- and 6-wk-exposed mice but not in single-exposed. Alveolar space and mean linear intercept were increased in 6- but not 3-wk-exposed mice. Caspase-3 and apoptosis protease activating factor-1 immunoreactivity was increased in the airway and alveolar epithelium and macrophages of 3- and 6-wk-exposed mice. Interleukin-13, keratinocyte chemoattractant, caspase-3, and IFN-γ mRNA were increased in the 6-wk-exposed group, but heme oxygenase-1 (HO-1) mRNA decreased. matrix metalloproteinase-12 (MMP-12) and caspase-3 protein expression increased in lungs of 6-wk-exposed mice. Collagen area increased and epithelial area decreased in airway wall at 3- and 6-wk exposure. Exposure of mice to ozone for 6 wk induced a chronic inflammatory process, with alveolar enlargement and damage linked to epithelial apoptosis and increased protease expression. 相似文献
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65.
Background
In humans, ethanol exposure during pregnancy causes a spectrum of developmental defects (fetal alcohol syndrome or FAS). Individuals vary in phenotypic expression. Zebrafish embryos develop FAS-like features after ethanol exposure. In this study, we ask whether stage-specific effects of ethanol can be identified in the zebrafish, and if so, whether they allow the pinpointing of sensitive developmental mechanisms. We have therefore conducted the first large-scale (>1500 embryos) analysis of acute, stage-specific drug effects on zebrafish development, with a large panel of readouts.Methodology/Principal Findings
Zebrafish embryos were raised in 96-well plates. Range-finding indicated that 10% ethanol for 1 h was suitable for an acute exposure regime. High-resolution magic-angle spinning proton magnetic resonance spectroscopy showed that this produced a transient pulse of 0.86% concentration of ethanol in the embryo within the chorion. Survivors at 5 days postfertilisation were analysed. Phenotypes ranged from normal (resilient) to severely malformed. Ethanol exposure at early stages caused high mortality (≥88%). At later stages of exposure, mortality declined and malformations developed. Pharyngeal arch hypoplasia and behavioral impairment were most common after prim-6 and prim-16 exposure. By contrast, microphthalmia and growth retardation were stage-independent.Conclusions
Our findings show that some ethanol effects are strongly stage-dependent. The phenotypes mimic key aspects of FAS including craniofacial abnormality, microphthalmia, growth retardation and behavioral impairment. We also identify a critical time window (prim-6 and prim-16) for ethanol sensitivity. Finally, our identification of a wide phenotypic spectrum is reminiscent of human FAS, and may provide a useful model for studying disease resilience. 相似文献66.
Sheikh A Khanam F Sayeed MA Rahman T Pacek M Hu Y Rollins A Bhuiyan MS Rollins S Kalsy A Arifuzzaman M Leung DT Sarracino DA Krastins B Charles RC Larocque RC Cravioto A Calderwood SB Brooks WA Harris JB Labaer J Qadri F Ryan ET 《PLoS neglected tropical diseases》2011,5(6):e1193
Background
Salmonella enterica serotype Typhi is a human-restricted intracellular pathogen and the cause of typhoid fever. Cellular immune responses are required to control and clear Salmonella infection. Despite this, there are limited data on cellular immune responses in humans infected with wild type S. Typhi.Methodology/Principal Findings
For this work, we used an automated approach to purify a subset of S. Typhi proteins identified in previous antibody-based immuno-affinity screens and antigens known to be expressed in vivo, including StaF-putative fimbrial protein-STY0202, StbB-fimbrial chaperone-STY0372, CsgF-involved in curli production-STY1177, CsgD- putative regulatory protein-STY1179, OppA-periplasmic oligopeptide binding protein precursor-STY1304, PagC-outer membrane invasion protein-STY1878, and conserved hypothetical protein-STY2195; we also generated and analyzed a crude membrane preparation of S. Typhi (MP). In comparison to samples collected from uninfected Bangladeshi and North American participants, we detected significant interferon-γ responses in PBMCs stimulated with MP, StaF, StbB, CsgF, CsgD, OppA, STY2195, and PagC in patients bacteremic with S. Typhi in Bangladesh. The majority of interferon-γ expressing T cells were CD4 cells, although CD8 responses also occurred. We also assessed cellular proliferation responses in bacteremic patients, and confirmed increased responses in infected individuals to MP, StaF, STY2195, and PagC in convalescent compared to acute phase samples and compared to controls. StaF is a fimbrial protein homologous to E. coli YadK, and contains a Pfam motif thought to be involved in cellular adhesion. PagC is expressed in vivo under the control of the virulence-associated PhoP-regulon required for intra-macrophage survival of Salmonella. STY2195 is a conserved hypothetical protein of unknown function.Conclusion/Significance
This is the first analysis of cellular immune responses to purified S. Typhi antigens in patients with typhoid fever. These results indicate that patients generate significant CD4 and CD8 interferon-γ responses to specific S. Typhi antigens during typhoid fever, and that these responses are elevated at the time of clinical presentation. These observations suggest that an interferon-γ based detection system could be used to diagnose individuals with typhoid fever during the acute stage of illness. 相似文献67.
Kangfeng Jiang Jing Yang Chao Yang Tao Zhang Aftab Shaukat Xiaoyan Yang Ailing Dai Haichong Wu Ganzhen Deng 《Journal of cellular and molecular medicine》2020,24(1):405-417
Endometritis is a postnatal reproductive disorder disease, which leads to great economic losses for the modern dairy industry. Emerging evidence indicates that microRNAs (miRNAs) play a pivotal role in a variety of diseases and have been identified as critical regulators of the innate immune response. Recent miRNome profile analysis revealed an altered expression level of miR‐148a in cows with endometritis. Therefore, the present study aims to investigate the regulatory role of miR‐148a in the innate immune response involved in endometritis and estimate its potential therapeutic value. Here, we found that miR‐148a expression in lipopolysaccharide (LPS)‐stimulated endometrial epithelial cells was significantly decreased . Our results also showed that overexpression of miR‐148a using agomiR markedly reduced the production of pro‐inflammatory cytokines, such as IL‐1β and TNF‐α. Moreover, overexpression of miR‐148a also suppressed NF‐κB p65 activation by targeting the TLR4‐mediated pathway. Subsequently, we further verified that miR‐148a repressed TLR4 expression by binding to the 3′‐UTR of TLR4 mRNA. Additionally, an experimental mouse endometritis model was employed to evaluate the therapeutic value of miR‐148a. In vivo studies suggested that up‐regulation of miR‐148a alleviated the inflammatory conditions in the uterus as evidenced by H&E staining, qPCR and Western blot assays, while inhibition of miR‐148a had inverse effects. Collectively, pharmacologic stabilization of miR‐148a represents a novel therapy for endometritis and other inflammation‐related diseases. 相似文献
68.
Richelle C. Charles Tania Sultana Mohammad Murshid Alam Yanan Yu Ying Wu-Freeman Meagan Kelly Bufano Sean M. Rollins Lillian Tsai Jason B. Harris Regina C. LaRocque Daniel T. Leung W. Abdullah Brooks Tran Vu Thieu Nga Sabina Dongol Buddha Basnyat Stephen B. Calderwood Jeremy Farrar Farhana Khanam John S. Gunn Firdausi Qadri Stephen Baker Edward T. Ryan 《PLoS neglected tropical diseases》2013,7(8)
Background
Salmonella enterica serotype Typhi can colonize and persist in the biliary tract of infected individuals, resulting in a state of asymptomatic chronic carriage. Chronic carriers may act as persistent reservoirs of infection within a community and may introduce infection to susceptible individuals and new communities. Little is known about the interaction between the host and pathogen in the biliary tract of chronic carriers, and there is currently no reliable diagnostic assay to identify asymptomatic S. Typhi carriage.Methodology/Principal Findings
To study host-pathogen interactions in the biliary tract during S. Typhi carriage, we applied an immunoscreening technique called in vivo-induced antigen technology (IVIAT), to identify potential biomarkers unique to carriers. IVIAT identifies humorally immunogenic bacterial antigens expressed uniquely in the in vivo environment, and we hypothesized that S. Typhi surviving in the biliary tract of humans may express a distinct antigenic profile. Thirteen S. Typhi antigens that were immunoreactive in carriers, but not in healthy individuals from a typhoid endemic area, were identified. The identified antigens included a number of putative membrane proteins, lipoproteins, and hemolysin-related proteins. YncE (STY1479), an uncharacterized protein with an ATP-binding motif, gave prominent responses in our screen. The response to YncE in patients whose biliary tract contained S. Typhi was compared to responses in patients whose biliary tract did not contain S. Typhi, patients with acute typhoid fever, and healthy controls residing in a typhoid endemic area. Seven of 10 (70%) chronic carriers, 0 of 8 bile culture-negative controls (0%), 0 of 8 healthy Bangladeshis (0%), and 1 of 8 (12.5%) Bangladeshis with acute typhoid fever had detectable anti-YncE IgG in blood. IgA responses were also present.Conclusions/Significance
Further evaluation of YncE and other antigens identified by IVIAT could lead to the development of improved diagnostic assays to identify asymptomatic S. Typhi carriers. 相似文献69.
In this study, we evaluated the effect of temperature on the development and reproductive biology of Serangium japonicum (Coleoptera: Coccinellidae) at seven constant temperature regimes (17, 20, 23, 26, 29, 32 and 35°C) for its effect as a predator of Bemisia tabaci (Homoptera: Aleyrodidae). Results indicated that the duration of the egg, larval and pupal stages were significantly affected by temperature. The developmental time gradually declined with the increase of temperature from 17 to 29°C, however an extension in the developmental periods was observed in the temperature range of 32 to 35°C. The survival rates of different insect stages were stable at temperatures between 20 and 32°C; however at extreme temperatures of 35°C, a sharp decrease was evident. The highest fecundity of the female (387.2 eggs per female) was recorded at 20°C. Based on these results, life tables of S. japonicum were constructed for temperatures in the range 20–35°C. The maximum reproductive rate (R 0=279.9) occurred at 26°C. The maximum values for innate capacity for increase (r m=0.1131) and the finite rate of increase (λ=1.1197) occurred at 29°C. The mean generation time (T) decreased with increased temperature, the longest of which was 76.0 days (at 20°C) and the shortest was 36.6 days (at 32°C). These results offer valuable insight on the importation and establishment of S. japonicum into new environments with diverse temperature regimes. 相似文献
70.
Baesman SM Bullen TD Dewald J Zhang D Curran S Islam FS Beveridge TJ Oremland RS 《Applied and environmental microbiology》2007,73(7):2135-2143
Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [epsilon] = -0.4 to -1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods ( approximately 10-nm diameter by 200-nm length), which cluster together, forming larger ( approximately 1,000-nm) rosettes composed of numerous individual shards ( approximately 100-nm width by 1,000-nm length). In contrast, Sulfurospirillum barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. 相似文献